The history of Asia can be seen as the collective history of several distinct peripheral coastal regions such as East Asia, South Asia, Southeast Asia and the Middle East linked by the interior mass of the Eurasian steppe. See History of the Middle East and History of the Indian Subcontinent for further details on those regions.
The coastal periphery was the home to some of the world's earliest known civilizations and religions, with each of three regions developing early civilizations around fertile river valleys. These valleys were fertile because the soil there was rich and could bear many root crops. The civilizations in Mesopotamia, ancient India, and ancient China shared many similarities and likely exchanged technologies and ideas such as mathematics and the wheel. Other notions such as that of writing likely developed individually in each area. Cities, states, and then empires developed in these lowlands.
The steppe region had long been inhabited by mounted nomads, and from